Chemical Agent Turns Tissue Transparent

Japanese researchers have developed a chemical agent that turns biological tissue transparent, allowing for vivid imaging of neurons and blood vessels deep inside mouse brains.

The aqueous reagent — referred to as Scale — offers a way of analyzing complex organs and networks in tissue samples, without having to dissect them into smaller pieces. Developed by Atsushi Miyawaki and his team at the RIKEN Brain Science Institute, Scale performs better than other clearing reagents because it doesn’t affect the shape or proportions of the sample. It also manages to avoid decreasing the strength of signals emitted by genetically-encoded fluorescent proteins in the tissue, which are frequently used by researchers as markers to flag up specific cells.

This means that neuroscientists can visualise fluorescently-labelled brain samples at a depth of several millimetres (as opposed to just one millimetre) and see neural networks at sub-cellular resolution. The team has used the agent to examine the neurons in a mouse brain and have been able to see the inner workings of the cerebral cortex, hippocampus and white matter. They have then been able to create 3D reconstructions of the neural networks, as you can see here.